Choosing the best microscope for wastewater treatment

With daily inspection using a decent quality wastewater treatment microscope, you can determine the biological health of your wastewater monitoring quickly and reliably.

The speed and ease of microscopic inspection makes it invaluable for early detection of potential problems (changes to F/M (food to microorganism ratio), bulking and shocks) – often before they can be detected by other methods.

However, you’ll need the right microscope for the task at hand – preferably with the following features to get the best results.

  • 100/400x magnification
  • quality lenses
  • phase contrast
  • trinocular head and digital camera
  • LED lighting
  • mechanical stage


You’re looking at microscopic organisms, so obviously you’ll be after a compound microscope. These microscopes combine an eyepiece lens (usually 10x magnification) with a series of objective lenses (usually 4x,10x,40x and 100x) to achieve 40 to 1000x levels of magnification.

For casual or routine inspections, you can probably skip the 100x lens, as most pertinent information in wastewater treatment – floc density and size and the presence of indicator organisms – can be found at lower magnification.

But for more serious exams, your best investment is a microscope with a 100x oil immersion lens. Its 1000x magnification lets you see finer details such as cell shapes, septa, diameter and the presence of storage materials, particularly in filamentous bacteria.

Lens quality

For most tasks (assess floc quality or identifying protozoa), you’ll do well enough with a standard resolution lens.

But for dealing with harder-to-identify organisms (filamentous bacteria), it will be worth your while to invest in higher quality objective lenses from a reputable brand. The extra resolution and clarity they provide are worth the expense.

Phase contrast

Most aquatic microorganisms are naturally translucent, so it can be difficult to make out details or internal structure without taking the time and trouble to stain them. It is therefore recommended when viewing microorganisms in wastewater monitoring to choose wastewater treatment microscope  with phase contrast.

While not strictly necessary, they are relatively cheap and provide excellent value by increasing the contrast of transparent specimens.

Because no harmful staining is involved, you’re also able to see your specimens alive and well in their natural habitat.

Trinocular head and camera

You can save yourself a lot of time and money through recording and reviewing key control parameters in your treatment system on a regular basis.

Photos and video from your microscope can be crucial to rapidly detecting biomass problems as they develop. This visual record can help you recognise and diagnose problems in sludge faster.

The easiest way to capture this information is with a trinocular head microscope. Tri heads have two eyepiece lenses (one for each eye) and a third port at the top for a camera. 

Reference photographs ensure a given situation is adequately described and made understandable for others. They’re also useful for training purposes.

As for the camera itself, there are options galore – ranging from a basic 2MP USB2 digital camera to  a high end HD Microscope Camera – so you won’t have any trouble finding the right camera for your budget and situation. Best to talk to us and discuss your requirements.

One tip though – be aware that some microscope cameras (particularly models using USB2.0 cables) don’t have a high enough frame-rate for taking high-res videos.

LED lighting

If you happen to be looking at the very cheapest microscopes or older second-hand models, try to find one with LED lighting.

LED lighting has largely replaced halogen bulbs, which came with drawbacks – namely, a shorter lifespan – and they produced enough heat to damage or kill specimens. Some models may still use the older lighting options, so be careful.

Mechanical stage

A mechanical stage is a platform that lets you move your slides smoothly and with much greater control than your hands. They are essential for working with high magnifications. If possible, try to ensure your microscope has one, or at least has the option of attaching one.

Tips for maintaining a healthy biomass

  • Know what your plant’s baseline ‘normal’ conditions look like. This will allow you to catch any problems early.
  • Conduct microscope evaluations frequently. Just how often will depend on your facility. Sometimes once every few sludge cycles is enough but, for facilities with chlorinated return activated sludge lines, daily inspection is appropriate. Frequent evaluations will help you catch issues before they get out of hand.
  • Use a reference sheet, preferably with photos, to help you identify microorganisms. Your exams will be faster and more reliable.
  • Even if you only have a cheap, basic microscope, it’s still worth doing routine inspections. You can get a good idea of the health of your biomass just by looking for indicator organisms and assessing floc size and density.

    Investing in a microscope for wastewater surveillance could be the best investment you’ve ever made.

    Wastewater Treatment Basic Phase Contrast Microscope

    The XSZ-107T-PHB Wastewater Treatment Basic Phase Microscope with Plan Objectives offers superior performance and a rich array of the most-used features all in an economical package.

    Combining our popular XSZ-107T Trinocular Biological Microscope with the Optico PLAN Phase Contrast Kit with quality Plan Objectives improves the imaging of transparent and colourless specimens, which are difficult to see or invisible when using an regular bright field microscope specially for observing living cells, microorganisms and bacteria.

    Optico XSZ-107T-PHB Phase Contrast Microscope (PLAN Objectives)

    Wastewater Treatment Advanced Phase Microscope

    BM2000-PH Phase Contrast Microscope (Infinity PLAN Objectives)

    • A complete turret phase contrast kit for infinity compound microscopes
    • Phase contrast turret iris diaphragm condenser
    • Centering Telescope lens to fit 23mm internal dismeter eyetubes
    • 3 phase contrast infinity Plan objectives, 10x, 40x and 100x OIL
    • Mounting size of condenser: 37mm in diameter

    Turret Phase Contrast Kit comprising of:

    • Phase Condenser with 3 position phase rings, 10X, 40X & 100X Oil Infinity Plan Achromatic Phase Objectives.
    • The condenser of this kit replaces the standard condenser on your microscope and the phase objectives should be used with the appropriate phase ring.
    • Once the condenser is properly aligned using the centering telescope (mounted as a temporary eyepiece), this kit will provide you with a phase contrast image of your specimens.

    BM2000-PH Phase Contrast Microscope (Infinity PLAN Objectives)

    Wastewater Treatment Professional Phase Microscope

    The Nikon Eclipse E200 Professional Phase Contrast Wastewater Treatment Microscope includes Phase Contrast Slider Kit (10x & 40x) and centering phase telescope with LED Illumination.

    Nikon Eclipse E-200 LED Phase Contrast Custom Configuration includes:

    • Nikon Eclipse E-200 LED Main Body
    • Choice of either Binocular or Trinocular head configuration
    • CFI Achromat Phase Objective Ph1 DL 10x N.A 0.25. W.D. 7.0
    • CFI Achromat Phase Objective Ph2 DL 40x N.A 0.65. W.D. 0.65
    • Pair CFI E 10X Eyepieces (FOV 20mm)
    • E200 Phase Contrast Condenser
    • S-PH1 Slider for Phase 10x & 40x
    • C-CT Centering Telescope with UW Adaptor

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